Condensed Consolidated Statements Of Cash Flows (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net issuances of commercial paper, discount	$ 0	$ 1
Pacific Gas And Electric Company [Member]
Net issuances of commercial paper, discount	$ 0	$ 1